title: A synthetic GFP-like chromophore undergoes base-catalyzed autoxidation into acylimine red form.
abstract: Fluorescent proteins are widely used in modern experimental biology, but much controversy exists regarding details of maturation of different types of their chromophores. Here we studied possible mechanisms of DsRed-type red chromophore formation using synthetic biomimetic GFP-like chromophores, bearing an acylamino substituent, corresponding to an amino acid residue at position 65. We have shown these model compounds to readily react with molecular oxygen to produce a highly unstable DsRed-like acylimine, isolated in the form of stable derivatives. Under the same aerobic conditions an unusual red-shifted imide chromophore--a product of 4-electron oxidation of Gly65 residue--is formed. Our data showed that GFP chromophore is prone to autoxidation at position 65 Cα by its chemical nature with basic conditions being the only key factor required.
authors.affiliation: Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, 117997 Moscow, Russia.
authors.forename: Pavel E
authors.initials: PE
authors.lastname: Ivashkin
authors.forename: Konstantin A
authors.initials: KA
authors.lastname: Lukyanov
authors.forename: Sergey
authors.initials: S
authors.lastname: Lukyanov
authors.forename: Ilia V
authors.initials: IV
authors.lastname: Yampolsky
mesh_terms: D000468:Alkalies / Q000737:chemistry; D019943:Amino Acid Substitution; D002384:Catalysis; D003500:Cyclization; D049452:Green Fluorescent Proteins / Q000138:chemical synthesis* / Q000378:metabolism; D007097:Imines / Q000737:chemistry; D008164:Luminescent Proteins / Q000737:chemistry*; D018716:Molecular Mimicry; D015335:Molecular Probes / Q000138:chemical synthesis*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism
chemical_list: D000468:Alkalies; D007097:Imines; D008164:Luminescent Proteins; D015335:Molecular Probes; C413663:fluorescent protein 583; D049452:Green Fluorescent Proteins; D010100:Oxygen